1. Field of the Invention
The invention relates to organosilanes and organopolysiloxanes which contain 2-oxazolidinone groups, where the oxazolidinone group is linked by the ring carbon atom C-4 or C-5 via a spacer to the silane or siloxane and the spacer is connected via a hydrolysis-stable Si--C bond to the silane or siloxane, to the use as surface-active substances and also to the use for preparing organosilanes and organopolysiloxanes containing amino or carbamido groups.
Oxazolidinone-functional silanes and polysiloxanes of the present invention have a high polarity and are easy to prepare. Because of their surface activity and their affinity to surfaces, the inventive compounds are used as additives in emulsion paints and surface coatings, for coating surfaces of pigments and fillers or in personal care and body cleansing products.
2. Description of the Related Art
To use polysiloxanes in polar media, it is necessary for polar groups to be built into the siloxane. Examples of siloxanes modified so as to be polar are polysiloxanes containing saccharide groups (U.S. Pat. No. 5,498,703), carbonate groups (DE-A-195 05 892), imidazoline groups (U.S. Pat. No. 5,496,478) and phosphate groups (U.S. Pat. No. 5,530,084). The compounds of the present invention represent a new class of organomodified polysiloxanes having particular properties.
There are many methods of preparing 2-oxazolidinones and these methods are described in the review article by M. E. Dyen and D. Swern (Chem. Rev., 67, 1967, 197-246). One method starts from epoxides which are reacted with nitrogen-containing reagents such as urea, alkyl carbamates or organic isocyanates. J. E. Herweh and W. J. Kauffman (Tetrahedron Letters, 12, 1971, 809-812) describe the lithium bromide-catalyzed reaction of epoxides with organic isocyanates in hydrocarbons as solvents to give N-substituted oxazolidinones. M. E. Dyen and D. Swern (J. Org. Chem., 33, 1968, 379-384) prepare N-unsubstituted oxazolidinones by the reaction of epoxides with potassium cyanate in dimethylformamide in the presence of tetraethylammonium bromide as catalyst. K. Kamagata (Nippon Kagaku Kaishi, 11, 1985, 2073-2076) isolated 5-(phenoxymethyl)-2-oxazolidinone from the reaction of phenyl glycidyl ether with isocyanuric acid in the presence of 2-methylimidazole.
DE-A-25 35 023 claims 5-(aryloxymethyl)-2-oxazolidinones, a process for their preparation from the corresponding epoxides using urea, as well as their use as medicaments. A. Huth and F. Neubauer (Liebigs Ann. Chem. 1979, 56-62) found that the yields of the reaction with urea are increased if dimethylformamide is used as solvent.
EP-B-0 425 209 describes the synthesis of N-naphthyl-substituted oxazolidinones from epoxides using N-naphthyl carbamates, while DE-A-26 30 107, GB-A-1 478 108, FR-B-2 281 114 and DE-A-29 02 129 describe the synthesis of N-unsubstituted oxazolidinones from epoxides using alkyl carbamates such as ethyl carbamate (urethane). EP-A-0 530 811 claims 5-(alkoxymethyl)- or 5-(alkenyloxymethyl)-2-oxazolidinones as well as a process for their preparation in which the corresponding epoxide is heated with a carbamate at temperatures above 150.degree. C. in the absence of solvent using a combination of a tertiary amine with a tin compound as catalyst.
Although the literature describes an organotrimethoxysilane (Recent Adv. Chiral Sep., [Proc. Chromatogr. Soc. Int. Symp. Chiral Sep.], 2nd (1990), Meeting Date 1989, 77-83. Editors: D. Stevenson, I. D. Wilson, Publisher: Plenum, New York, N.Y.) and also a monofunctional organodisiloxane (Nippon Kagaku Kaishi, 5, 1990, 566-574 and Gan to Kagaku Ryoko, 7, 1980, 1942-1951) which contains an oxazolidinone group, in both those compounds the ring nitrogen bears a benzyl or phenyl substituent. There are no known oxazolidinone-functional organosilanes or organo-siloxanes where the oxazolidinone ring bears a hydrogen or short-chain alkyl radical on the nitrogen. The absence of aromatic substituents on the nitrogen allows for the retention of the polar character of the oxazolidinone group thereby providing the compounds, in particular the polysiloxanes which are nonpolar by nature, a high compatibility with polar media.
A further advantage of the polysiloxanes of the invention compared to the known monofunctional disiloxane is that the ratio of (polar) oxazolidinone and (nonpolar) siloxane groups can be set to any desired value and can thus be tailored to the respective application.